vsiles
Posts: 41
Joined: Wed Feb 04, 2015 10:04 am

Rpi 2/3 irq

Thu Mar 03, 2016 8:50 pm

Hi ! From what I gathered, neither pi2 nor pi3 has a gic.
1) anybody knows why ? This is really a shame (and a pain, gic is cool)
2) I can't find anywhere in the doc how to choose to which core I want my interrupts délibérés (like timer sp804's irq , not ppi/mailboxes). Is it even possible or do I have to route them only to core 0 and then use sgi's/mailboxes ?

Best,
V

dradford
Posts: 18
Joined: Mon Feb 15, 2016 3:33 pm

Re: Rpi 2/3 irq

Fri Mar 04, 2016 2:21 pm

For IRQ routing on Pi2, try page 11 of this: https://www.raspberrypi.org/documentati ... rev3.4.pdf

vsiles
Posts: 41
Joined: Wed Feb 04, 2015 10:04 am

Re: Rpi 2/3 irq

Fri Mar 04, 2016 3:57 pm

I'm not sure I got it right. Using this registre, can I:
- route 2 special irqs named GPU irq/fiq to a single core only
- route all peripheral irq (like sp804) to a single core

In both case, I can route every thing to one core only, I can't dispatch per core.

If anyone can provider a better/correct explanation, that would be great !

dradford
Posts: 18
Joined: Mon Feb 15, 2016 3:33 pm

Re: Rpi 2/3 irq

Sat Mar 05, 2016 9:50 am

You nominate 1 core to handle all peripheral interrupts. Other interrupts (like inter-core mailboxes) are routed separately. But it looks like you can send IRQ and FIQ to different cores, so if you don't mind losing FIQs you could divert ONE of the gpu interrupts to a separate core as an FIQ.

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